JP5169686B2 - Camshaft lubricator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply oil pressure from a head side oil passage formed on a bearing member to a phase variable mechanism without a large drop thereof and give no harmful effect on a rolling bearing itself when a camshaft is supported by a bearing member of a cylinder head through the rolling bearing. <P>SOLUTION: An adjacent bearing member 20 positioned adjacently to the phase variable mechanism 30 is supported by the camshaft 1 through the rolling bearing 50. Annular space A, B (annular groove parts 25, 26) having centers on the camshaft 1 are formed between the adjacent bearing member 20 and the surfaces of diameter expanded flange parts 2, 3 formed on the camshaft 1 opposing in an axial direction. Head side oil passages 61, 65 and camshaft side oil passage 62, 66 (67) are communicated to the annular spaces A, B. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a camshaft oiling device.

Many engines, particularly automobile engines, change the phase of the opening / closing timing of intake valves or exhaust valves. For this phase change, a hydraulic phase variable mechanism is provided at one end of the camshaft of the intake valve or exhaust valve, and by changing the hydraulic supply mode to this phase variable mechanism, the camshaft relative to the crankshaft is changed. Some change the phase. In general, oil supply to the hydraulic phase variable mechanism is performed from the head side oil passage in the bearing member supporting the cam shaft through the oil passage in the cam shaft.

In Patent Document 1, when a cam shaft is rotatably supported via a roller bearing, which is a kind of rolling bearing, with respect to a bearing member provided in a cylinder head, one end side in the axial direction of a roller bearing retainer is disclosed. A side oil passage is formed on the side, and the head side oil passage formed in the bearing member and the cam shaft side oil passage formed in the cam shaft are communicated with each other through the side oil passage. Is disclosed. Patent Document 1 also discloses that a seal portion that seals the lateral oil passage is formed at the axial end portion of the roller bearing retainer. Patent Document 2 discloses that when the cam shaft is supported by a slide bearing, the head side oil passage and the cam shaft side oil passage communicate with each other via a sliding surface between the cam shaft and the slide bearing. Has been.

JP 2008-101714 A JP 9-250310 A

By the way, when the camshaft is supported by a rolling bearing, the rolling bearing itself has a very weak hydraulic pressure holding function. For this reason, the head-side oil passage and the camshaft-side oil passage are communicated using the space in the rolling bearing. This is a decrease in the hydraulic pressure supplied to the hydraulic leakage toe phase variable mechanism, which is virtually impossible to employ. In addition, if a large amount of oil flows into the rolling bearing, the rolling resistance increases, which is not preferable. Furthermore, as described in Patent Document 1, forming a lateral oil passage on the side of one end side in the axial direction of the cage of the roller bearing increases the axial length of the portion related to the roller bearing.

The present invention has been made in view of the above circumstances, and its object is to provide a head-side oil passage formed in the bearing member when the camshaft is supported by the bearing member of the cylinder head via the rolling bearing. Another object of the present invention is to provide a camshaft oiling device that can supply the oil pressure from the shaft to the phase variable mechanism without greatly reducing the oil pressure, and that does not adversely affect the rolling bearing itself.

In order to achieve the above object, the following first solution is adopted in the present invention. That is, as described in claim 1 in the claims,
A cam shaft provided with a hydraulic phase variable mechanism at one end is rotatably supported by a bearing member of a cylinder head, and a cam shaft side formed on the cam shaft from a head side oil passage formed on the bearing member In a camshaft lubrication device that lubricates the phase variable mechanism via an oil passage,
An adjacent bearing member located next to the phase variable mechanism among the bearing members supports the camshaft via a rolling bearing,
Before hear beam axis is restricted from being displaced in the axial direction, and said rolling bearing so as to sandwich the axial direction a pair of enlarged diameter flange portion provided,
Respectively between the facing surfaces opposed to each other in close proximity in the axial direction between the adjacent bearing member and said pair of enlarged diameter flange portion, the rolling annular space in the diametrically outside of the bearing about said cam shaft The annular groove to be formed is formed in the enlarged diameter flange or the adjacent bearing member,
An advance oil passage continuing to the advance working chamber of the phase variable mechanism; and a retard oil passage continuing to the retard working chamber;
The head-side oil passage has an advance-angle head-side oil passage for supplying oil to the advance-angle working chamber, and a retard-angle head-side oil passage for supplying oil to the retard-angle working chamber;
The advance angle head side oil passage and the advance angle oil passage communicate with one annular groove portion of the pair of annular groove portions, and the retard angle head side oil passage communicates with the other annular groove portion. The corner oilway is in communication,
It is like that.

According to the above solution, the adjacent bearing member adjacent to the phase varying mechanism among the bearing members receives an external force in a direction intersecting the axial direction due to a tension from a chain or a timing belt wound around the phase varying mechanism. Therefore, the rotational resistance is particularly increased. However, the rotational resistance can be greatly reduced by supporting the camshaft with the adjacent bearing member with the rolling bearing. Further, the oil is supplied from the head side oil passage to the phase variable mechanism through the annular space without causing a great decrease in hydraulic pressure. Of course, since the space in the rolling bearing is not used as a hydraulic pressure supply path to the phase variable mechanism, a large amount of oil does not flow into the rolling bearing and its rotational resistance does not increase. It becomes. Further, it is not necessary to separately form an extra space for oil passage formation on the side of the rolling bearing, and the cam shaft can be positioned in the axial direction by the enlarged diameter flange portion.
In addition to the above, by dividing the two annular groove portions into two enlarged diameter flange portions, the two annular groove portions can be formed in a different radial direction relative to one enlarged diameter flange portion. As a result, the outer diameter of the enlarged diameter collar can be reduced, and the resistance between the enlarged diameter collar and the adjacent bearing member can be reduced accordingly. In addition, the pair of enlarged diameter flanges can reliably prevent the cam shaft from being inadvertently displaced in both axial directions.

A preferred mode based on the first solution is as set forth in claims 2 to 5 in the claims. That is,
The pair of enlarged diameter flanges are formed on the cam shaft,
The annular groove is formed only in the pair of enlarged diameter flanges,
(Corresponding to claim 2). In this case, considering that the bearing member is usually constituted by a cylinder head and a cap member different from the cylinder head, it is easy to process the annular groove portion with respect to the enlarged diameter flange portion of the cam shaft which is a shaft object.

Of the pair of enlarged diameter flanges, an adjacent enlarged diameter flange part closer to the phase variable mechanism is configured by an end wall part of the phase variable mechanism, and the other enlarged diameter flange part is formed on the cam shaft. It is, are then way (claim 3 corresponds). In this case, the end wall portion of the phase variable mechanism is also used as the enlarged diameter flange portion, which is preferable for simplifying the cam shaft.

The phase variable mechanism has an urging unit that urges either the advance working chamber or the retard working chamber in a compressing direction.
The annular groove formed in the far diameter enlarged collar portion located on the side farther from the phase variable mechanism of the pair of diameter enlarged collar portions is the attachment of the advance working chamber and the retard working chamber. For the working chamber on the side not compressed by the biasing means,
(Corresponding to claim 4 ). In this case, the hydraulic pressure supply path from the annular groove located far from the phase variable mechanism to the phase variable mechanism becomes longer, and the resistance of the hydraulic pressure supply increases accordingly. By preventing the hydraulic pressure from resisting the urging force of the urging means, it is possible to prevent a situation in which the hydraulic pressure supply time greatly differs between the hydraulic pressure supply to the advance working chamber and the hydraulic pressure supply to the retard working chamber. This is preferable in terms of suppression.

A drain oil passage is formed in the adjacent bearing member so as to face a lower portion of the rolling bearing (corresponding to claim 5 ). In this case, it is preferable to reliably prevent a situation in which a large amount of oil stays in the rolling bearing and to prevent a situation in which the rotational resistance of the rolling bearing increases.

According to the present invention, while restricting the position of the camshaft, using a rolling bearing, the rotational resistance of the camshaft is reduced, and the hydraulic pressure from the head side oil passage is supplied to the phase variable mechanism without greatly decreasing. can do. Further, it is preferable for shortening the axial length of the portion where the rolling bearing is disposed as much as possible.

Hereinafter, an embodiment of the present invention will be described by taking as an example a case where it is applied as a camshaft oiling device for an automobile engine. In FIG. 1, reference numeral 1 denotes a camshaft, which is used for driving an exhaust valve in the embodiment. The cam shaft 1 is rotatably supported by the cylinder head 10, and a cam shaft supporting bearing member provided on the cylinder head 10 is indicated by reference numeral 20. Note that a plurality of cam shaft support bearing members are provided at intervals in the axial direction of the cam shaft 1, but only the bearing member 20 provided on one end side of the cam shaft 1 is shown in FIG. The bearing member 20 is an adjacent bearing member.

A phase variable mechanism 30 is assembled on one end side of the cam shaft 1. As shown in FIG. 2, the phase variable mechanism 30 roughly includes an outer member 31 and an inner member 32. The outer member 31 has a large number of teeth 35 on its outer peripheral surface. A chain or timing belt driven by a crankshaft (not shown) is wound around (engaged with) the tooth portion 35, and the crankshaft and the outer member 31 are always rotated integrally.

The inner member 32 is fixed to the cam shaft 1 while being in contact with one end of the cam shaft 1 from the axial direction, and is always rotated integrally with the cam shaft 1. In the embodiment, the inner member 32 is fixed to the camshaft 1 by a bolt 33 in a state in which the inner member 32 is aligned with a positioning pin (not shown) with respect to the camshaft 1. As shown in FIG. 2, a plurality of recesses 36 are formed on the inner peripheral surface of the outer member 31 at intervals in the circumferential direction. A convex portion 37 that protrudes into the concave portion 36 is formed on the outer peripheral surface of the inner member 32. Within each recess 36, an advance working chamber 38 and a retard working chamber 39 are defined by a projecting portion 37. In FIG. 2, when the hydraulic pressure is supplied to the advance working chamber 38 (the hydraulic pressure is discharged from the retard working chamber 39) while the phase variable mechanism is rotating clockwise, the inner member 32 moves to the outer member 31. In contrast, the camshaft 1 is rotated relative to the clockwise direction in FIG. 2 to advance the camshaft 1 with respect to the crankshaft. Conversely, when hydraulic pressure is supplied to the retarding working chamber 39 (hydraulic discharge from the advance working chamber 38), the inner member 32 is rotated relative to the outer member 31 counterclockwise in FIG. The shaft 1 is retarded with respect to the crankshaft.

The inner member 32 is urged in the advance direction with respect to the outer member 31 by a coil spring 34 as urging means. That is, when the hydraulic pressure is supplied to the advance working chamber 38, the advance is made while being assisted by the urging force of the coil spring 34,
When the hydraulic pressure is supplied to the retarding working chamber 39, the retarding is performed while resisting the urging force of the coil spring 34. The outer member 31 is restricted from relative displacement in the axial direction with respect to the inner member 32. In FIG. 1, an advance angle internal oil passage continuously connected to the advance angle working chamber 38 formed in the phase variable mechanism 30 (in the inner member 32 in the embodiment) is indicated by reference numeral 41, and is used for the retard angle. A retarding internal oil passage that is always connected to the working chamber 39 is indicated by reference numeral 42.

As shown in FIG. 3 in particular, the bearing member 20 includes a lower holding portion 21 formed in the cylinder head 10 and a cap member 23 fixed to the cylinder head 10 by bolts 22. The camshaft 1 is rotatably supported via a rolling bearing 50 in a state of being sandwiched between the lower holding portion 21 and the cap member 23 from the vertical direction. As known, the rolling bearing 50 includes an outer ring 51, a cage 52, and a large number of needle-shaped rollers 53. The retainer 52 has a cylindrical shape, and a large number of storage spaces are formed at intervals in the circumferential direction. A roller 53 is stored and held in each storage space. With such a cage 53, the roller 53 is positioned in the axial direction and the circumferential interval between the rollers 53 is ensured. The rolling bearing 50 has a half structure and is assembled to the cam shaft 1 from the radially outer side.

A pair of enlarged diameter flanges 2 and 3 are integrally formed on the camshaft 1 so as to sandwich the bearing member 20 from the axial direction. The pair of enlarged diameter flange portions 2 and 3 restricts the cam shaft 1 from being displaced relative to the bearing member 20 in the axial direction. Each of the pair of enlarged diameter flange portions 2 and 3 extends radially outward so that the side surface (axial end surface) faces the side surface of the bearing member 20.

The pair of enlarged diameter flange portions 2 and 3 are opposed to the adjacent bearing member 20 (the lower holding portion 21 or the cap member 23) in a state of being close to each other in the axial direction, and a gap between the opposed surfaces is as much as possible. It is set as the small clearance made small (it may be in the state which is lightly contacted and slid). An annular annular groove 25 centered on the camshaft 1 is formed on the opposite surface of the enlarged diameter flange 2 facing the bearing member 20, and an annular space A (annular groove 25 is formed by the side surface of the bearing member 20. Is formed). Similarly, an annular groove portion 26 centering on the camshaft 1 is formed on the opposed surface of the enlarged diameter flange 3 facing the bearing member 20, and an annular space B ( Corresponding to the annular groove 26). Each of the annular groove portions 25 and 26 is formed on the radially outer side from the rolling bearing 50.

A head-side oil passage 61 formed in the bearing member 20 (cap portion 23) communicates with the annular space A (annular groove portion 25) located on the left side in FIG. The head-side oil passage 61 is opened on the surface of the bearing member 20 that faces the enlarged-diameter flange 2, and the opening position is constant. However, even if the camshaft 1 is rotated, Therefore, the communication state is maintained. The annular groove 25 is communicated with the retarding internal oil passage 42 in the phase variable mechanism 30 via the camshaft side oil passage 62 formed in the enlarged diameter flange portion 2. In this way, the retarding hydraulic pressure is supplied from the head side oil passage 61 to the retardation working chamber 39 via the annular groove 25, the camshaft side oil passage 62, and the retarding internal oil passage 42. (The hydraulic pressure is discharged from the retarding working chamber 39 through this reverse path). FIG. 4 shows a state in which the annular groove 25 is viewed from the axial direction (the annular groove 26 is also formed in the same manner as in FIG. 4).

A head-side oil passage 65 formed in the bearing member (cap member 23) is communicated with the annular space B (annular groove portion 26) located on the right side in FIG. In other words, the head-side oil passage 65 is opened in the surface of the bearing member 20 that faces the enlarged diameter flange portion 3, and the opening position thereof is constant, but even if the camshaft 1 is rotated, the annular groove portion 26 is formed. On the other hand, the communication state is maintained. The annular groove 26 is always in communication with the advance internal oil passage 41 in the phase variable mechanism 30 via cam shaft side oil passages 66 and 67 formed in the cam shaft 1. In this way, the hydraulic pressure for the advance angle is supplied from the head side oil passage 65 to the advance angle working chamber 38 through the annular groove 26, the cam shaft side oil passages 66 and 67, and the advance angle internal oil passage 41. (The hydraulic pressure is discharged from the advance working chamber 38 through this reverse path).

1 and 3, the bearing member 20 is formed with a drain oil passage 24 opened on the upper surface of the lower holding portion 21. The drain oil passage 24 extends downward and opens to the outside (valve chamber) from the side surface of the bearing member 20. An oil escape hole 51a communicating with the drain oil passage 24 is formed at the bottom of the outer ring 51 of the rolling bearing 50 (see FIG. 3).

In the configuration as described above, since the bearing member 20 is supported by the rolling bearing 50, the cam shaft 1 has a small rotational resistance. In particular, the bearing member 20 is subjected to a large external force in the direction orthogonal to the axial direction due to the tension from the chain or timing belt wound around the phase variable mechanism 30, but the camshaft 1 is driven by the rolling bearing 50. It will rotate smoothly.

Further, the hydraulic pressure for the advance angle or the retard angle to the phase variable mechanism 30 is supplied via the annular space A or B (annular groove portion 25 or 26), that is, bypassing the rolling bearing 50. Thus, the oil pressure is supplied to the phase variable mechanism 30 without causing a large oil pressure leak from the rolling bearing 50 portion, that is, without causing a large decrease in the oil pressure. A part of the hydraulic pressure supplied to the annular spaces A and B (annular groove portions 25 and 26) performs appropriate lubrication between the opposing surfaces, while the enlarged diameter flange portions 2 and 3 and the bearing member 20 The roller bearing 50 is supplied to the rolling bearing 50 through a minute gap between the opposing surfaces to moderately lubricate the roller bearing 50, but a large amount of oil is not supplied to the roller bearing 50 from the minute gap.

Note that the oil that has flowed into the rolling bearing 50 is discharged through the drain oil passage 24, and it is reliably prevented that a large amount of oil is stored in the rolling bearing 50 (a large amount of oil in the rolling bearing 50). (Prevents increase in rotational resistance due to oil accumulation). Further, the cam shaft 1 is reliably prevented from being accidentally displaced in the axial direction by the pair of enlarged diameter flange portions 2 and 3 (maintaining accurate positioning).

As described above, the urging force of the coil spring 34 is set in the direction of assisting the advance angle. For this reason, in order to promptly change the phase of the phase variable mechanism 30 in the retarding direction, the hydraulic pressure supply path for the retarding working chamber 39 is set so that the hydraulic pressure is supplied to the retarding working chamber 39 as quickly as possible. The length is shorter than the hydraulic pressure supply path for the advance working chamber 38. That is, as shown in FIG. 1, a short hydraulic pressure supply path that passes through the annular groove 25 formed in the enlarged diameter flange portion 2 on the side close to the phase variable mechanism 30 is selected for the retarding working chamber 39. . Thereby, the response of the hydraulic pressure supply is made substantially the same at the advance angle and the retard angle. Further, as is apparent from FIG. 1, the pair of annular groove portions 25, 26 are formed in a distributed manner on the pair of enlarged diameter flange portions 25, 26, and are positioned on the same radius of the cam shaft 1 as cams. The position is set as close as possible in the radial direction of the shaft 1, which is preferable for shortening the length of the oil passage as much as possible.

FIG. 5 shows a second embodiment of the present invention. The same components as those in the above embodiment are given the same reference numerals, and redundant description thereof is omitted (this is the case of the third embodiment described below). The same applies to the following forms). In this embodiment, the enlarged diameter flange portion 2 on the side close to the phase variable mechanism 30 is configured by the end wall portion 32 a on the bearing member 20 side of the phase variable mechanism 30. This makes it unnecessary to form the one enlarged diameter flange portion 2 on the cam shaft 1, which is preferable in simplifying the cam shaft 1. Further, in the present embodiment, the head side oil passages 61 and 65 are provided in the lower holding portion 21 of the bearing member 20 (it is unnecessary to form the oil passage long upward to the cap member 23). In addition, it is unnecessary to form the head side oil passage through the mating surface between the lower holding portion 21 and the cap member 23).

FIG. 6 shows a third embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 1 in that the head side oil passages 61 and 65 are provided in the lower holding portion 21 of the bearing member 20.

FIG. 7 shows a reference example . In this reference example , of the pair of left and right enlarged diameter flanges 25 and 26, one of the enlarged diameter flanges 25 close to the phase variable mechanism 30 is provided with the respective annular groove portions 25 and 26 for advance and retard. It has been formed. In this reference example , the annular groove portions 25 and 26 are concentratedly formed (processed) with respect to one of the enlarged diameter flange portions 2, and the formation of the other enlarged diameter flange portion 3 is facilitated.

Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . The phase variable mechanism 30 may be used for the intake valve (assembled to the intake valve camshaft). The advance and retard annular grooves 25 and 26 may be provided on the bearing member 20 side . End wall portion 32a which serves to expand diameter collar portion 2, integrated into unless integrally molded to the inner member 32, the inner member 32 constituted by a separate member, the inner member 32 by a fixture such as a bolt or the like It may be what you did. For example, in the embodiment of FIG. 1, the pair of enlarged diameter flange portions 2 and 3 are formed separately from the cam shaft 1 without being integrally formed with the cam shaft 1, and are integrated with the cam shaft 1 by a fixture or the like. It may be what you did. The urging direction by the coil spring 24 may be opposite to the embodiment. The head side oil passages 61, 65 or the cam shaft side oil passages 62, 66, 67 communicated with the annular spaces A, B (annular grooves 25, 26) are not limited to one, A plurality may be provided at intervals in the circumferential direction. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

1 is a side cross-sectional view showing a first embodiment of the present invention. FIG. 2 is a cross-sectional view corresponding to line X2-X2 in FIG. 1. FIG. 3 is a cross-sectional view corresponding to line X3-X3 in FIG. 1. X4-X4 line equivalent sectional drawing of FIG. Sectional drawing which shows the 2nd Embodiment of this invention and respond | corresponds to FIG. Sectional drawing which shows the 3rd Embodiment of this invention and respond | corresponds to FIG. Sectional drawing which shows a reference example and respond | corresponds to FIG.

A, B: Annular space 1: Cam shaft 2: Expanded flange portion 3: Expanded flange portion 10: Cylinder head 20: Bearing member 21: Lower holding portion 23: Cap member 24: Drain oil passage 25: Annular groove portion (For retarded angle)
26: annular groove (for advance angle)
30: Phase variable mechanism 31: Outer member 32: Inner member 34: Coil spring (biasing means)
36: concave portion 37: convex portion 38: advance working chamber 39: retard working chamber 41: advance internal oil passage 42: retard internal oil passage 50: rolling bearing 51: outer ring 52: cage 53: Roller 61: Head side oil passage (for retarded angle)
62: Cam shaft side oil passage (for retarded angle)
65: Head side oil passage (for advance angle)
66: Cam shaft side oil passage (for advance angle)
67: Cam shaft side oil passage (for advance angle)

Claims (5)

A cam shaft provided with a hydraulic phase variable mechanism at one end is rotatably supported by a bearing member of a cylinder head, and a cam shaft side formed on the cam shaft from a head side oil passage formed on the bearing member In a camshaft lubrication device that lubricates the phase variable mechanism via an oil passage,
An adjacent bearing member located next to the phase variable mechanism among the bearing members supports the camshaft via a rolling bearing,
Before hear beam axis is restricted from being displaced in the axial direction, and said rolling bearing so as to sandwich the axial direction a pair of enlarged diameter flange portion provided,
Respectively between the facing surfaces opposed to each other in close proximity in the axial direction between the adjacent bearing member and said pair of enlarged diameter flange portion, the rolling annular space in the diametrically outside of the bearing about said cam shaft The annular groove to be formed is formed in the enlarged diameter flange or the adjacent bearing member,
An advance oil passage continuing to the advance working chamber of the phase variable mechanism; and a retard oil passage continuing to the retard working chamber;
The head-side oil passage has an advance-angle head-side oil passage for supplying oil to the advance-angle working chamber, and a retard-angle head-side oil passage for supplying oil to the retard-angle working chamber;
The advance angle head side oil passage and the advance angle oil passage communicate with one annular groove portion of the pair of annular groove portions, and the retard angle head side oil passage communicates with the other annular groove portion. The corner oilway is in communication,
A camshaft oiling device characterized by that. In claim 1,
The pair of enlarged diameter flanges are formed on the cam shaft,
The annular groove is formed only in the pair of enlarged diameter flanges,
A camshaft oiling device characterized by that. In claim 1 ,
Of the pair of enlarged diameter flanges, an adjacent enlarged diameter flange part closer to the phase variable mechanism is configured by an end wall part of the phase variable mechanism, and the other enlarged diameter flange part is formed on the cam shaft. It is, camshaft lubrication system, characterized in that. In any one of Claims 1 thru | or 3 ,
The phase variable mechanism has an urging unit that urges either the advance working chamber or the retard working chamber in a compressing direction.
The annular groove formed in the far diameter enlarged collar portion located on the side farther from the phase variable mechanism of the pair of diameter enlarged collar portions is the attachment of the advance working chamber and the retard working chamber. For the working chamber on the side not compressed by the biasing means,
A camshaft oiling device characterized by that. In any one of Claims 1 thru | or 4 ,
A camshaft oiling device, wherein a drain oil passage that faces a lower portion of the rolling bearing is formed in the adjacent bearing member.

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